1. Field of the Invention
The present invention relates to an optical fiber suitably used for wavelength division multiplexing (WDM) transmission in the wavelength range from 1420 nm to 1520 nm, a dispersion compensator using the optical fiber and an optical transmission system.
2. Description of the Related Art
Developments of the information society have increasingly promoted increase of a communication information amount, and such an increase of the communication information amount makes causes wavelength division multiplexing transmission to be widely used in the communications field. The wavelength division multiplexing transmission is a system for transmitting light having plural wavelengths with one optical fiber.
Recently, an optical amplifier using an erbium-doped optical fiber (EDFA) has been developed as an optical amplifier applicable to a relay portion of the wavelength division multiplexing transmission. At present, installation of EDFA at a relay portion of the wavelength division multiplexing transmission makes it unnecessary to convert optical signals to electrical signals every wavelength at the relay portion, and this merit is promoting the developments of the wavelength division multiplexing transmission.
The optical amplification band of EDFA is in the wavelength range from 1520 nm to 1565 nm (called as xe2x80x9cC-bandxe2x80x9d), or in the wavelength range from 1565 nm to 1620 nm (called as xe2x80x9cL-bandxe2x80x9d). At present, studies on the wavelength division multiplexing transmission using the above wavelength bands are actively performed.
Furthermore, in order to support a further increase of the communication information amount, it has been recently considered to carry out the wavelength division multiplexing transmission in the wavelength range from 1420 nm to 1520 nm (called as xe2x80x9cS-bandxe2x80x9d). The wavelength division multiplexing transmission in the S-band is carried out by applying TDFA (Thulium-Doped Fiber Amplifier) or Raman fiber amplifier.
The present invention has an object to provide an optical fiber having the following construction, a dispersion compensator using the optical fiber, and an optical transmission system.
The optical fiber according to the present invention is characterized in that the chromatic dispersion at a set wavelength in the wavelength range of or more 1420 nm but less than 1520 nm is set to xe2x88x928 ps/nm/km or less.